does unique means with no gaps or just monotonic ? Should that data be an integer ? there are tons of ways to have unique numberings just based on the fact that any given branch can produce a limited amount of invoices in a preset period of time. If, e.g., your company usually issues 50k invoices a year (more than a hundred a day, more than 4k a month) for any given "branch", assuming branches are 30.....
a good scheme is 2 places for the current year --- 13 2 places for the "branch code" -- 01, 02, 03, etc 5 places for the "monotonic" counter ---- 00001 to 50000 (heck, if they start issuing invoices for every pen bought by employees, you can reach 100k invoices a year) this basically compose a number that is 130100001 to 130199999 for the "first branch" 130200001 to 130299999 for the "second branch" and so on. given the previous assumptions, you'd likely end up at the end of the year having 130100001 to 130149999 130200001 to 130249999 In any case, those kind of integers are fully representable with a normal "int" field, that in most dbs holds values from 0 to 2^31 ... that is 2147483647. Don't worry. Even if your app still works in 2113, you'd still reach 1135099999 for the latest invoice of the latest branch that is far beyond the theoretical limit of ints. If you want to spend 8 bytes for every invoice number instead of 4, you can still go with bigint and you could generate zillions of invoices a year for a zillion branches for a zillion years. Where's the issue ? -- Resources: - http://web2py.com - http://web2py.com/book (Documentation) - http://github.com/web2py/web2py (Source code) - https://code.google.com/p/web2py/issues/list (Report Issues) --- You received this message because you are subscribed to the Google Groups "web2py-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
